Non- small cell lung cancer( NSCLC) is the most common type of lung cancer. Molecular targeted therapy is the most promising development part in the treatment of NSCLC. In recent years,more and more attention has been focused on some new molecular targets in NSCLC,such as echinodem microtubule- associated protein- like4 / anaplastic lymphoma kinase( EML4- ALK) fusion gene. This review will focus on the basic structure,advance research and the inhibitor of anaplastic lymphoma kinase Crizotinib.